Alzheimer's: Spatial navigation issues in midlife may predict risk

Ad

12 28, 2024

An older woman standing outside blows bubblesShare on Pinterest
Experts say impairments in spatial navigation could be one of the warning signs of Alzheimer’s risk. Rebecca Nelson/Getty Images
  • Impairments in spatial navigation might be an early warning sign for Alzheimer’s disease, according to a new study.
  • Researchers said men showed more spatial navigation impairment than women.
  • They noted that spatial impairment might develop years or decades before symptoms of Alzheimer’s appear.

A virtual reality test looking at spatial navigation in midlife adults might provide an early screening tool for Alzheimer’s disease.


That’s according to a study published today in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.


Researchers at the University College of London used a virtual reality set to test spatial navigation in 100 adults between the ages of 40 and 59, about 25 years younger than their estimated age of dementia onset.


None of the participants showed symptoms of Alzheimer’s. However, they did have a hereditary or physiological risk of the disease, including a family history of the condition or lifestyle risk factors such as low physical activity levels.


Participants were from the PREVENT-Dementia cohort study.


“Spatial difficulties are very common in those with Alzheimer’s, both men and women,” said Dr. Douglas Scharre, a professor of clinical neurology and psychiatry as well as the director of the Division of Cognitive Neurology at the Center for Cognitive and Memory Disorders with the The Ohio State University Wexner Medical Center.


“This task involves the use of many parts of the brain and so just to classify it as spatial difficulties is an oversimplification,” Scharre, who wasn’t involved in the study, told Medical News Today. “You have to estimate how far and in what direction you need to go. Also, problem-solving skills and judgments are required to be accurate.”


The researchers reported that the people at the most significant risk of developing Alzheimer’s, regardless of risk factors, were selectively impaired on the virtual reality navigation task without a corresponding impairment on other cognitive tests.


Spatial navigation and Alzheimer’s disease

The study authors said the findings suggest that impairments in spatial navigation may begin to develop years or decades before the onset of other symptoms of dementia.


They added that men showed more spatial impairment than women.


“This type of research can be compelling, as early detection of cognitive impairment using novel technologies such as virtual reality is potentially valuable, especially when the virtual reality tasks are targeting specific brain functions related to specific neuropathologies,” said Ryan Glatt, CPT, a senior brain health coach and director of the FitBrain Program at Pacific Neuroscience Institute in California who was not involved in the study.


This type of technology will likely not be used to diagnose conditions such as Alzheimer’s on its own but can be part of a clinical workup that includes validated diagnostics, and ‘exploratory biomarkers’ such as performance on a virtual reality task,” Glatt told Medical News Today. “However, much more research is needed to have tasks like these be reliable, repeatable, sensitive, and valid diagnostics.”


Predicting Alzheimer’s before significant thinking and functional loss in a person who may develop the disease later in life is important because scientists are currently developing potential disease-modifying therapies, Scharre pointed out.


“We do not know, based on this study, that this technology can offer an earlier diagnosis as we do not know if any of these individuals will or will not ever get [Alzheimer’s disease],” he said. “It is possible that it can be predictive. The difficulty with the technology is that it is not the most practical of assessments. You need the machine, the software, the space to run the test, trained administrators, and a way to get the results back to the patient. It may be difficult to use this technology with patients in underserved or under-resourced areas. As with any test, there will be false positive and false negative results. In general, there is promise with these cognitive biomarkers.”


Some cautions about the Alzheimer’s study

The authors of the study acknowledge certain limitations, such as its relatively small sample size and that some trials were excluded due to limitations of space in which to conduct virtual reality assessments.


Dr. Mike Gorenchtein, a geriatrician at Northwell Lenox Hill Hospital and the Zucker School of Medicine in New York who wasn’t involved in the research, pointed out other potential limitations:


“As immersive virtual reality spatial technology continues to evolve, it may serve a role in earlier Alzheimer’s disease diagnosis,” Gorenchtein told Medical News Today. “Given the relatively young age of the study subjects (approximately two decades before the estimated age of onset for dementia) and because we do not know whether the subjects with path-integration impairments went on to develop dementia, replication of similar studies over longer periods of time and with a greater sample size would help validate whether this technology can offer an earlier disease diagnosis.”


“Another important point is that there may be baseline variation among healthy individuals, and even genders, in their natural ability to adapt to virtual reality testing environments and performance,” he added. “Hence, deficits in virtual reality visuospatial testing should ideally correlate with other clinical and neuropsychological features of early cognitive impairment to make an accurate diagnosis.”


The importance of early detection of Alzheimer’s

Several medical conditions and lifestyle factors might contribute to the development of Alzheimer’s disease.


These include:


  • Increasing age
  • Diabetes
  • Smoking
  • High blood pressure
  • Elevated cholesterol
  • Obesity
  • Depression
  • Low level of physical activity
  • Infrequent socialization
  • Infrequent participation in mentally stimulating activities
  • The presence of the APO-E4 gene variant

The likelihood of developing Alzheimer’s increases with more than one of these risk factors.


“Early symptoms that may be associated with Alzheimer’s might include recurring memory, organizational, and visuospatial challenges,” Glatt said. “Regardless of whether individuals believe a symptom is an early indicator of Alzheimer’s or not, it is critical to consult one’s doctor and seek out specialists for expert opinion.”


“Early detection of cognitive decline can lead to the pursuit of more comprehensive assessment, treatment, and management of neurodegenerative conditions,” he added.


Benefits of an early diagnosis include:


  • Allowing people to take control of their condition, access support and services as well as providing them the opportunity to live independently for longer.
  • Helping them preserve a good quality of life.
  • Permitting them to plan for their healthcare, financial, and legal concerns when they still can actively participate in decisions.
  • Letting them access treatments that could potentially improve their cognition.

Experts say early detection and diagnosis also help caregivers.


They can better adapt and might experience less anxiety and depression. It also gives them extra time to come to terms with the diagnosis and learn about treatments and what to expect in the future.


“Since there is currently no cure for Alzheimer’s disease, both the older medications and the newer disease-modifying therapies (such as the monoclonal antibodies, lecanemab, and aducanumab) are largely aimed at slowing the rate of cognitive decline,” Gorenchtein explained. “The newly approved monoclonal antibodies are also costly and carry significant side effects. Early disease diagnosis is therefore extremely valuable to identify patients who may gain the greatest benefit from treatment. Early diagnosis can also help guide patients and families in planning their lifestyles, such as prioritizing personal, professional, and financial goals.”